Yarn steaming apparatus



y 2, 1967 J. c. DAVIS YARN STEAMING APPARATUS 5 Sheets-Sheet 1 Filed Dec. '23, 1964 May 2, 1967 J. c. DAVIS YARN STEAMING APPARATUS 5 Sheets-Sheet 2 Filed Dec. 23, 1964 m p g. 2 Q

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YARN STEAMING APPARATUS Filed Dec. 23, 1964 5 Sheets-Sheet I5 y 2, 67 J. c. DAVIS 3,316,740

YARN STEAMING APPARATUS Filed Dec. 23, 1964 5 Sheets-Sheet 4 United States Patent 3,316,740 YARN STEAMING APPARATUS James Campbell Davis, Chattanooga, Tenn., assignor to E. I. du Pont de Nemours and Company, Wilmington, DeL, a corporation of Delaware Filed Dec. 23, 1964, Ser. No. 420,547 6 Claims. (Cl. 686) This invention relates to improved apparatus for applying steam to yarn, and more particularly to nylon filaments and yarns.

Commercially available nylon yarn is usually produced by melt-spinning polyamide filaments, winding the undrawn yarn into a package and subsequently drawing the yarn. In order to provide a satisfactory package of undrawn yarn for the subsequent drawing operations, it has been found advantageous to apply steam to the yarn subsequent to quenching and prior to winding into a package.

Prior methods of steaming running lengths of yarn have generally involved passing steam concurrently or countercurrently with the yarn passage. This does not, however, uniformly treat the filaments and results in a non-uniform product. Other devices providing for treatment transverse to the yarn flow have not been able to maintain substantially uniform fiow of small quantities of high quality steam (no condensate) at relatively high velocities across the yarn, which is essential to achieving uniform yarns and filaments.

It is therefore an object of this invention to provide improved apparatus for steaming filaments and yarns.

It is another object to provide improved apparatus for applying steam transversely to freshly spun filaments and yarns in a uniform, non-turbulent fashion.

A further object is to provide steaming apparatus which is readily threaded.

Other objects and advantages will become apparent from the description and discussion to follow.

These objects are accomplished by the following invention which, in apparatus having an elongated chamber for steaming running lengths of yarn, includes steam inlet means along one side of said chamber for uniformly passing steam transversely to the path of the yarn passing therethrough, and steam outlet means positioned along the opposite side of said chamber.

Yarn is herein used to refer to continuous strands of textile fibers, filaments, or material in a form suitable of intertwining to form a textile fabric.

Apparatus for carrying out this invention is shown by way of example in the attached drawings in which:

FIGURE 1 shows a perspective view of a preferred form of apparatus;

FIGURE 2 is a cross-sectional view taken along line 2-2 of FIGURE 1;

FIGURE 3 is a cross-sectional elevation view taken along line 3-3 of FIGURE 2;

FIGURE 4 is a cross-sectional View of an alternate embodiment corresponding to FIGURE 2 of the preferred embodiment;

FIGURE 5 is a cross-sectional elevation view taken along line 5 -5 of FIGURE 4;

FIGURE 6 is a cross-sectional view taken along line 6-6 of FIGURE 5; and

FIGURE 7 shows a cross-section of a modified form of the alternate embodiment of FIGURE 4.

Referring in more detail to the preferred form of apparatus (FIGURES l, 2 and 3), high pressure steam is introduced through steam inlets 2 at the top of the apparatus and flows downwardly in elongated outer chamber 4. Some of the steam from the pressurized outer chamber 4 is vented into an elongated inner chamber 6 through metering orifices 8, while the excess steam, together with any condensate, passes out through steam outlet 10. The steam passing out of outlet 10 may preferably be fed to a steam trap and vented to the atmosphere, or it may be returned to the steam supply. Excess steam is provided in outer chamber 4 to maintain uniform flow of high quality steam through the metering orifices 8 at relatively high velocity. The metering orifices 8 enable the control of the quantity of steam being fed to inner chamber 6.

As the steam enters the elongated inner chamber 6, it is distributed throughout the length of the chamber by impinging against curved screen 12. Depending on the mesh of the screen 12, the velocity of the steam may be broken up as desired to provide uniform, non-turbulent flow of the steam as it passes to a steaming chamber 14. The screen 12 as shown in FIGURE 3 does not extend the full length of the inner chamber 6, but could if so desired. The steam, after being distributed by screen 12, enters an elongated steaming chamber 14 through inlet means 16 which consists preferably of a foraminous steam distributor plate. From the elongated chamber 14 the steam is vented to the atmosphere through steam outlet means 18, which also serves as a string-up slot to facilitate loading the running lengths of yarn 20 into the steaming chamber 14.

The steam orifices 8 in the preferred embodiment (FIG- URES 2 and 3) are located on opposite sides of inner chamber 14 to direct the incoming steam toward curved screen 12 and away from the distributor plate. Where the apparatus is no more than 10 to 12 inches in length, one orifice 8 on each side of the inner chamber 6 is usually suificient, but additional orifices may be employed if desired. For convenience, it i desirable that access plugs 22 be provided in the outer jacket of outer chamber 4 opposite each orifice 8.

The foraminous distributor plate may consist of one or more fine screens such as a combination of two IOO-mesh, two 200-mesh, and six 325-mesh screens. Alternatively and preferably, a perforated metal plate such a inch thick porous stainless steel plate having pores of about microns diameter is used. To operate efficiently of course, the distributor plate should have a porosity such that there will be at least a slight positive pressure within inner chamber 6. Accordingly, the size of the pores may vary somewhat depending on the rate of steam flow.

Preferably the steamer is provided with an outer layer of a suitable insulating material 24 to reduce heat loss to the atmosphere.

Although a curved screen 12 is shown and described, a solid aluminum baffle of the same configuration has been found to be equally useful to distribute the steam and break up its velocity. Both the screen and bafile could be of various other configurations as long as placed in the path of the incoming steam from the metering orifices 8 to distribute the steam.

In use, the steamer is generally mounted on the spinning machine in the desired position along the yarn path. If desired, a yarn convergence guide 26 (FIGURE 1) may be mounted directly on top of the steamer to converge the filaments as they pass into the steaming chamber 14. The running lengths of yarn 20 are generally introduced into chamber 14 through the steam outlet means and string-up slot 18.

In a typical operation of a 12-inch steamer, high pressure steam at -100 p.s.i.g. is fed to the outer chamber 4 as a rate of 4 p.p.h. (pounds mr hour). Steam is vented through orifices 8 at a rate of about 0.85 p.p.h. The steam is distributed first by the screen 12 (or baffle) and then by the foraminous distributor plate. The steam then flows uniformly through the steaming chamber 14 transversely to the path of the running lengths of yarn and out through narrow stringup slot 18. Under these conditions, treatment of the yarn is uniform and threadline stability in steaming chamber 14 is good.

When lower pressures are used, an alternate embodiment (FIGURES 4, 5 and 6) may be used. It employs the same principles and varies only slightly from the structure of the preferred embodiment. Here the high pressure steam is introduced through inlet 102 at the bottom of the apparatus, flows upwardly through a steam supply passage 104, through connecting passageway 130 and then downward into the elongated outer chamber 106. A condensate outlet 110 is provided at the bottom of the outer chamber 106. Some of the steam from pressurized outer chamber 106 is vented through orifice 114 into an elongated inner reheat chamber 112, while the remainder of the steam passes out through outlet 108 where it is fed to a steam trap and vented to the atmosphere. As the steam enters the inner reheat chamber 112, it is distributed by impingement against the eliptical steam supply passage 104 rather than a curved screen as in the preferred embodiment. The distributed steam then enters the elongated steaming chamber 118 through inlet means 116 which consists of a foraminous distributor plate as described above. From the steaming chamber 118 the steam is vented to the atmosphere through outlet means 120, which also serves as a stringup slot for loading the yarn 126 into chamber 118.

Here the steam orifice 114 is located in the rear center of the wall of inner chamber 112 if only one orifice is employed. If a plurality of orifices are employed, they are preferably distributed uniformly along the length of the inner chamber 112. The remainder of the apparatus is substantially as described above.

The reheat tube or steam supply passage 104 is here employed in place of the curved screen 12 to prevent condensate forming in the inner chamber 112. In the preferred embodiment, at high pressures of 15-100 p.s.i.g. no problem is encountered. However, from about 1 to 10 p.s.i.g. especially, it is found that reheat means must be provided in the inner chamber to assure high quality steam (no condensate). The tube 104 further acts to distribute the steam, thus preventing the need of a curved screen. Of course, this alternate embodiment would also be useful at higher pressures.

More than one yarn end may also be passed through this alternate embodiment by appropriate sizing of the elongated steaming chamber and metering orifices. If this is done, it may be desirable to use two or more reheat tubes and two or more steam orifices to provide uniform treatment of the several yarns. FIGURE 7 shows one such modification for steaming four yarns 126' simultaneously. Two steam supply passages or tubes 104', fed by two steam inlets 102', and two steam orifices 114 are employed in this design, the orifices being mounted at either side of the reheat chamber 112'. The steam supply passages 104' enters the two pressurized outer chambers 106 through the connecting passagewaytnot shown) and enters the reheat chamber 112 through the two orifices 114. Excess steam is vented out of the outer chambers 106' through two steam outlets 103' to the steam trap. Condensate from the outer chambers 106' is removed through the two condensate outlets 110'. As the steam enters the reheat chamber 112, it is distributed and heated by impinging against the two steam supply passages 104, and then enters the elongated steaming chamber 113' through inlet means 116 (a foraminous steam distributor plate). After the steam transversely contacts the four running lengths of yarn 126 it passes out the outlet means 120, which again serves as a string-up slot.

The yarn steaming apparatus of this invention has the advantage over the prior art of providing in the steaming zone uniform flow of small quantities of high quality steam at relatively high velocity transverse to the yarn path. The excess high pressure steam maintained in the pressurized outer chamber insures uniform flow rate of high quality steam entering the reheat chamber. The orifice(s) and distributing means (screen or tube) provide a lower flow rate and substantially even distribution to prevent turbulence in the steaming zone. The steam supply passage of the alternate embodiment also reheats the steam to prevent condensation. The distributor plate further distributes the steam and assures non-turbulent flow. The prior art devices cannot be utilized satisfactorily with these small quantities and flow rates without encountering difificulties due to low quality steam (with condensate) and uneven distribution. Failure to provide uniform conditions leads to excessive variations in the yarn denier which causes undesirable non-uniformities in fabrics.

It is desirable that the filaments be converged prior to steaming to avoid filament to filament denier variations arising from fluctuation of the individual filaments in the elongated steaming chamber. With a converged bundle, it is found that steam flow parallel to the yarn path does not provide uniform treatment of the filaments. Steam flow substantially transverse to the yarn path, as provided in the apparatus of this invention, is satisfactory in this respect. Apparatus of this invention has the further advantage of being readily threaded through a string-up slot (steam outlet means). This is essential in modern, high speed spinning operations.

It is to be understood that the foregoing description is by way of example only and that various modifications and changes in the details may be made without departing from the spirit of the invention and the scope of the following claims.

What is claimed is:

1. In an apparatus having an elongated steaming chamber for steaming running lengths of yarn, elongated steam inlet means positioned along one side of said chamber for uniformly passing high quality steam substantially transverse to the path of yarn passing through said chamber and elongated steam outlet means positioned along the opposite side of said chamber.

2. Claim 1 wherein the steam inlet means comprises an elongated foraminous plate.

3. Claim 1 wherein the steam outlet means is a longi tudinal string-'up slot.

4. In the apparatus of claim 1, means for supplying lgigh quality steam to said steam inlet means at a substantially uniform flow rate, said means for supplying steam comprising an elongated inner chamber adjacent to and communicating with the steam inlet means of said steaming chamber, a pressurized outer chamber in heat exchange relationship with the outside of said inner chamber for supplying high quality steam thereto, and distributing means mounted within said inner chamber to distribute said steam along said inner chamber for passage through the steam inlet means of said steaming chamber.

5. Claim 4 wherein said distributing means is a curved aluminum baflle.

6. In the apparatus of claim :1, means for supplying high quality steam to said steam inlet means at a substantially uniform flow rate, said means for supplying steam comprising an elongated inner reheat chamber adjacent to and communicating with said steam inlet means, a pressurized outer chamber in heat exchange relationship with the outside of said reheat chamber for supplying steam thereto, and a steam supply passage extending 10ngitudinally through said reheat chamber for supplying high pressure steam to said outer chamber and for reheating and distributing the steam within said reheat chamber.

References Cited by the Examiner UNITED STATES PATENTS McEnaney 68-6 Ceasar 68-6 Helle 68-6 Richeson et al. 68-5 Carter 68-5 Yazawa et al 68-43 X 10 IRVING BUNEVICH, Primary Examiner, 

1. IN AN APPARATUS HAVING AN ELONGATED STEAMING CHAMBER FOR STEAMING RUNNING LENGTHS OF YARN, ELONGATED STEAM INLET MEANS POSITIONED ALONG ONE SIDE OF SAID CHAMBER FOR UNIFORMLY PASSING HIGH QUALITY STEAM SUBSTANTIALLY TRANSVERSE TO THE PATH OF YARN PASSING THROUGH SAID CHAMBER AND ELONGATED STEAM OUTLET MEANS POSITIONED ALONG THE OPPOSITE SIDE OF SAID CHAMBER. 